Evaluación del aceite agrícola para el control del pulgón (Brevicory brassicae) en la col morada (Brassica oleracea var. Capitata f. rubra)

Abstract

Aphids represent a serious threat to the production of different species of the Brassicaceae group worldwide, including the cabbage aphid, Brevicoryne brassicae, which can cause significant economic losses. Therefore, the use of synthetic pesticides is required, which has resulted in the development of pest resistance and effects on human health and the environment, for which the use of mineral oils or agricultural oils can offer results that could be used in the control of pest insects in different crops. In this regard, in the present study the effect of agricultural oil on the control of the aphid, B. brassicae in cabbage (Brassica oleracea var. capitata f. rubra) was evaluated. The effect of different doses (7.5, 10.0 and 12.5 cc/l) of the agricultural oil applied at different ages of the crop (80, 90 and 100 days after transplantation) on the effectiveness in the aphid management was evaluated. The trial was conducted in a completely randomized design with the treatments in a factorial arrangement in which the first factor was represented by the dose of agricultural oil, the second factor the date of application. Initial population of B. brassicae varied from 122.3 to 284.5 aphids/plant, while after 10 days of application (90 days of cultivation) the population was significantly low, reaching only 88.3 aphids on plants where agricultural oil was applied at the 7.5 cc/l, while at doses 10 and 12.5 cc/l, the number of aphids reached 49.8 and 60.8 aphids/plant, respectively. After 100 days of cultivation, the population showed a slight increase, reaching between 113.6 and 172.6 aphids/plant at a dose of 7.5 and 10.0 cc/l, respectively. The greatest effectiveness was observed with the doses of 10 and 12.5 cc/l, with which the percentage of effectiveness varied from 72.16 and 78.43% with the application 80 days of the crop. Similarly, the effectiveness increased to 84.91 and 85.74 %, with the highest dose (12.5 cc/l) applied at 90 and 100 days of culture. A similar effect was observed during the second and third application of agricultural oil. According to the Probit analysis, an LD50 of 11.513 cc/l was observed with a slope for the dose-mortality curve of 4.788 ± 0.679. In conclusion, an effect of the dose was observed, but not of the moment of application of the agricultural oil on the control efficiency of the cabbage aphid, for which it is suggested to incorporate its use in a pest management program in cabbage crop.